1. Field of the Invention
This invention relates to the field of chemistry. More particularly, this invention relates to dye lasers. Still more particularly, but without limitation thereto, this invention relates to a method of obtaining a long-lived flashpumped laser dye with an output equivalent to commercial dyes and with a low threshold of lasing.
2. Description of the Prior Art
The class and wavelength of laser dyes of interest are in the range of 560 to 585 nm. More specifically, the desirable lasing wavelength is 560. This particular wavelength region has rhodamine dyes (strongest output) that lase, yet they have lower lifetimes. Other dyes in this region include brilliant sulfaflavine, fluoral 555 (both with low outputs) and shifted coumarin dyes.
Research has been done with oxazoles yet they have shown little success as flashlamp-pumpable laser dyes. Considerable improvement was shown when molecular engineering was performed on the oxazoles to make them more absorptive and to attach triplet-state quenchers to them. However, the lasing outputs of the modified oxazoles were still low compared to other classes of dyes.
Salts of a pyridyl substituted phenyloxazole in water have exhibited relatively low laser outputs and moderate durations of lasing with flashlamp pumping. The effects of dye structure, cover gas and solvent are all critical to laser output and lifetime. This invention establishes that under very specific experimental conditions, one of the oxazole dye modifications yields the highest lifetime with moderate laser output of any laser dye solution reported. See A. N. Fletcher, R. A. Henry, R. F. Kubin and R. A. Hollins, Fluorescence and Lasing Characteristics of Some Long-Lived Flashlamp-Pumpable, Oxazole Dyes, Optics Com. 48, pp. 352-356 (1984).